there are very few calculations you need to know. off the top of my head, some of those are odds ratio, relative risk, and hardy-weinberg. in general, physiology equations do not need to be memorized, but you should know the concepts.
e.g. increase vessel diameter, decrease resistance.
e.g. oncotic and hydrostatic pressure oppose each other and a drop in one causes flow from one compartment to the other.
e.g. inulin approximates GFR
e.g. if you stick an acid in a more acidic environment it will be protonated, if you stick it in a base it will be deprotonated
as pox mentioned, working backward is a nice workaround. it's pretty surprising how often that trick works... at least when it comes to qbank and my limited exposure to step1 questions of that sort. look at the units, make up some way of getting those units, and see what number you get.
edit based on post below:
definitely know sensitivity, specificity, PPV, NPV.
definitely know clearance.
